The present invention relates to a connection, in particular the connection between purlins and hip roof trusses, for hip roof construction. A hip roof, or hipped roof, is a type of roof where all sides slope downwards to the walls, usually with a fairly gentle slope. Thus it is a house with no gables or other vertical sides to the roof. A square hip roof is shaped like a pyramid. Hip roofs on rectangular houses will have two triangular sides and two trapezoidal ones. A hip roof on a rectangular plan has four faces. They are almost always at the same pitch or slope, which makes them symmetrical about the centerlines. Hip roofs have a consistent level fascia, meaning that a gutter can be fitted all around. Hip roofs often have dormer slanted sides.
Hip roofs are more difficult to construct than a gabled roof, requiring somewhat more complex systems of trusses. Although the roof itself is harder to construct, the walls that carry the roof are easier to build, being all one level. Hip roofs can be constructed on a wide variety of plan shapes. Each ridge is central over the rectangle of building below it. The triangular faces of the roof are called the hip ends, and they are bounded by the hips themselves. The hips sit on an external corner of the building and rise to the ridge. Where the building has an internal corner a valley makes the joint between the sloping surfaces. They have the advantage of giving a compact, solid appearance to a structure.
In modern domestic architecture, hip roofs have been seen to represent comfort, practicality, and solidness. They are thus commonly seen in bungalows and cottages, and have been integral to styles such as the American Foursquare. However, the hip roof has been used in many different styles of architecture and in a wide array of structures. A hip roof is self-bracing. It does not need the same amount of diagonal bracing (wind bracing) that a gable roof requires.
A hip roof is also ideal to have in hurricane regions. It holds up much better to high winds. In areas like Northern Australia, or the Gulf Coast of the Southeastern United States, that are subject to high wind loadings and strict construction codes this could be a factor in deciding which type of roof to build. If the slope of the roof from horizontal is 35 degrees or greater it will reduce/eliminate the airfoil effect of extreme high winds that blow over the roof and a hip roof is far less likely to peel off the house than a gable end roof. To this end, since 2001 the State of Florida has required insurance companies to offer a premium discount to customers who can prove they have a hip roof, which they do by obtaining a windstorm inspection. The hip roof also exhibits increased survivability in tornado winds and hurricanes. They are stable.
One advantage of a hip roof is that it has eaves all round. These protect the walls from the weather and help to shade the walls (and the windows in them) from the sun, thus reducing the power needed to cool the structure in warm climates. A gable roof does not shade the walls at the gables.
In architecture or structural engineering or building, a purlin is a generally horizontal structural member in a roof. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and/or the building walls, steel beams etc. The use of purlins, as opposed to closely spaced rafters, is common in pre-engineered metal building systems and some timber frame construction.
In lightweight timber roof construction under purlins are used to support rafters over longer spans than the rafters alone could span. Under purlins are typically propped off internal walls. For example, an 8×4 under purlin would support the center of a row of 6×2 rafters that in turn would support 3×2 roof purlins to which the roof cladding was fixed.
In traditional timber truss construction purlins are supported by the principal rafters of the truss.
In all metal or mixed building roof systems, purlin members are frequently constructed from cold-formed steel, (or roll formed) C or Z sections. The Z sections can be lapped and nested at the supports which creates a continuous beam configuration between the bays. When C and Z sections are used in wall construction it is normal to call them girts.
The present invention replaces cut-to-size (and angle) purlins and temporary braces with permanent connectors that brace the connected structural members and permit sheathing to be applied directly thereover. The present invention provides a sloped surface for attaching the sheathing or decking of the roof in a convenient and efficient manner when stepped hip ridge trusses are used, without having to shape the top chords of the trusses to the particular slope of the roof or to cut individual purlins.